Field of the Invention
The present invention relates to an ink jet recording apparatus.
Description of the Related Art
In an ink jet recording method, a liquid composition containing a coloring material (ink) is directly or indirectly applied onto a recording medium such as paper to form an image. During the process, the recording medium may excessively absorb a liquid component in the ink, thereby causing curing or cockling.
In order to immediately remove the liquid component in an ink to suppress such trouble, there are a method of drying a recording medium by using warm air, infrared light, or a similar technique and a method in which an image is formed on a transfer body, then a liquid component contained in the image on the transfer body is dried by thermal energy or the like, and the image is transferred to a recording medium such as paper.
Another method is disclosed as the technology of removing the liquid component contained in an image on a transfer body without using thermal energy. In the method, a roller-like porous body is brought into contact with an ink image to absorb and remove the liquid component from the ink image (Japanese Patent Application Laid-Open No. 2009-45851).
Another method is disclosed as the technology for removing water from an image formed by an ink on a recording medium. In the method, liquid removal conditions are optimized when a liquid removal roller is used (Japanese Patent Application Laid-Open No. 2006-306079). In Japanese Patent Application Laid-Open No. 2006-306079, the water content on the surface of a roller for liquid removal from images on a recording medium is measured by a moisture sensor, and liquid suction conditions of the liquid roller or contact conditions of the liquid roller with images are changed on the basis of the measurement result to optimize the liquid removal conditions.
The measurement of the water content of an object to be measured by a moisture sensor is, however, performed by bringing the moisture sensor into contact with the object to be measured. When such a contact-type sensor for measuring a water content is repeatedly brought into contact with the surface layer of a roller for liquid removal, the surface layer of the roller may be scratched, and this may reduce the liquid removal efficiency from images to cause image defects.